Abstract
Background Atypical electroencephalogram (EEG) abnormalities emerge in patients with subacute
sclerosing panencephalitis (SSPE), especially in cases with an atypical clinical presentation
that can lead to diagnostic difficulties.
Case Report In this article, we presented a case of SSPE with an atypical onset with epileptic
seizures and Parkinson's features. The neurological examination during the initial
evaluation of the patient showed extrapyramidal syndrome, hyperreflexia, intention
tremor, and dysmetria. Cranial magnetic resonance imaging was normal. Video EEGs were
performed in wakefulness and sleep. In wakefulness, multiple brief seizures (1–1.5 seconds
were recorded, consisting of gradual bending of the body forward and to the right
that lacked the sudden characteristic of myoclonia. During those episodes, we recorded
generalized epileptiform activity of 4 or 5 sharp waves, with higher amplitude in
the anterior regions, in some of the paroxysms superimposed on a slow wave or followed
by a high amplitude slow wave. The paroxysms appeared periodically every 15 to 30 seconds.
However, 2 months later, the EEG showed typical periodic generalized activity of biphasic/triphasic
slow waves (Radermecker complexes), accompanied by myoclonias.
Conclusion We reported a peculiar EEG pattern in a patient with SSPE that consists of periodic
generalized activity of sharp waves. Atypical EEG patterns can appear when the disease
progresses, but initially too, before typical periodic complexes and can complicate
the diagnostic process.
Keywords
EEG periodic discharges - subacute sclerosing panencephalitis - measles
